| 摘要 |
The invention discloses a density and viscosity sensor for measuring density and viscosity of a fluid, wherein the sensor (1) comprises: a housing (4) defining a chamber (8) isolated from the fluid (3), the housing (4) comprising an area defining a membrane (9) separating the chamber (8) from the fluid (3); a resonating element (5) arranged to be immersed in the fluid (3) and mechanically coupled to the membrane (9); and an actuating/detecting element (6) coupled to the resonating element (5), the actuating/detecting element (6) being positioned within the chamber (8) and mechanically coupled to the membrane (9), the actuating/detecting element (6) comprising at least one piezoelectric element (10) comprising two sides (11, 12) substantially parallel to the membrane (9). The membrane (9) has a thickness enabling transfer of mechanical vibration between the actuating/detecting element (6) and the resonating element (5). The sensor is further characterized in that: one side (11) of the piezoelectric element (10) comprises a single conductive area (13); and another side (12) of the piezoelectric element (10) comprises at least two conductive areas (14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H) isolated from each other, each conductive area (14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H) being coupled to an electrical potential (V1, V2) of opposite sign relatively to adjacent areas such that the resonating element (5) is driven to vibrate in a selected plane (P1, P2)perpendicular to the membrane (9). |
